Oil burner



J. T. MCGRATIH Feb. 20, 1923..

OIL BURNER Filed Apr. 24, 1919 n "IIIIIIIII K RN Patented li'eb, 20, lgg

irrtN tiene '1r orties.

OIL BURNER.

Application filed April 24, 1919. Serial No. 292,295.

To all y'erlitt/lf2, t mcy concern Be it known that i, JOHN T. MOGRATH, a citizen oit the United States, and a resident ot Bloomington, in the county ot McLean and State ot illinois, have invented certain new and useful Improvements in @il Burners; and I do hereby declare that the following is a tull, clear, and exact description thereof, reference being had to the accompanying drawings, and to the characters of reference marlred thereon, which form a part ot' this speciiication.

This invention relates to improvements in oil burners adapted to be used in connection with fuel oil furnaces tor any desired purpose and to which the iuel oil and air are ted underpressure and are intel'- mixed under pressure to produce an atomized fuel constituent which, at the furnace, is delivered into a large volume of lovv pressure air to carry the mir-:ture generated to the point ont application of the heat.

Among the objects et the invention is to provide improved means for mixing air with y the fuel oil so constructed and arranged that the supply means can be very delicately adjusted to accurately obtain a properly proportioned mixture. y

A :tui-ther object of the invention is to provide an improved auxiliary air inlet to admit an auxiliary supply ot tree air to the burner which is adapted to be mined With the pressure oil `and air at the immediate point of mixture ot the latter and in a manner to obtain a uniform desired mixture.

[i .Further object ot the invention is to provide a novel construction of the burner head to bring the air and oil together and to agitate the oil at the point Where the air iirst contacts with it so as to produce better atomization.

Another object ot the invention is to provide in combination with the air and tuel mixing elements of a high pressure burner. means yfor admitting at the 'furnace the biu'ning mixture along with a large volume ot lov: pressure air as furnished by a fan bh "t so arranged relatively to the high pr V4ure mixture outlet as to gently bring the full heat ot the flame on the material being heated in a manner to slowly saturate the. material with heat and to avoid burning the material. i 1

Other objects ot' the invention are to generally simplify and improve oil burners7 and the invention consists in the combination and arrangement ot' the parts shown in the drawings' and described in the specification, and is pointed out `in the appended claims.

In said drawings7 Figure 1 is a vertical section of an oil burner embodying my invention.

Figure 2 is a rear end `View of the burner head.

Figure 3 is a transverse section on the line 3 3 of Figure 1. l

rFigure 4t is a perspective detail showing the adjustment for the furnace air inletl valve. -v

Figure 5 is a detail on line` 5 5 of Figure 2.

As shown in the drawings, designates an elbow shaped casing or conduit, comprising a horizontal outlet member 11 which is adapted to extend into the furnace and a downv'ardly extending receiving member l2 adapted to be connected to ayblast tan to furnish air in volume at a loW pressure through the conduit to the furnace. The flow of air through the casing is controlled by a butterfly valve 13, the operating handle 14 ot which is engaged by stops 15 and 16 to arrest the valve in its open or closed position. Said valve 13 is adaptedto be locked in adjusted positions between its limits of movement by the spring pressed paw] lil shown` in Figure 4 carried by the vaive shaft to engage stopopenings 12 in wall of inlet 12. Said valved elbow casing constitutes air` inlet conduit of large cubical contents adapted to controllably conduct air in `a large volume and at relatively low pressure to the furnaceLto be intermixed with the iame ot' the high pressure burner7 so as to distribute the flame to and cause it to softly impinge on the material being heated. Tie saidv inlet is, therefore, a volume` low pressure, air inlet.

1T designates a mixing tube or chamber which extends axially through the outlet member oi the voluma low pressure casing. lt is made of considerably smaller diameter than 'the outlet or discharge oriiice of the low pressure conduit and is designed to discharge-burning mixture under high pressure through the core ot the relatively loiv pressure, large volume ot air delivered through the conduit outlet or discharge orifice. Said tube is seated in athiclrened hollowv portion 18 et said casing at the exterior angle et llo the junction of the members thereof and is held inplace bya set screw 19. Made integral with said tube 17 or fixed thereto in any suitable manner is, what may be termed, a feed head designated as a whole by 20, Said head is provided Witha branch or connection 2l interiorly threaded to receive a liquid fuel pipe adapted to deliver fuel under pressure to said head. The head is provided inside said connection with a liquid fuel receiving chamber 22 which is formed in a transverse, cored outmember 23 ofthe head. rfhe said chamber 22 terminates at its upper end in a seat 2e, shown herein as a conical seat, which is engaged by a valve 25 that is held on the seat by a spring 26, whose pressure is adapted to be regulated by an adjusting screw 27 that is threaded in the head and extends into a chamber 23 in the member 23 in which said spring is contained. 28 designates an open port leading from the chamber 23just above the valve seat to a mixing chamber 29 that is in open communication with the receiving end of the mixing tube.

The head is formed in rear of the member 23 with an air inlet chamber 30 to receive air, and said chamber is in open communi.- cation with the mixing chamber 2) through passages 30 around the sides of the meinber 23. The head is also provided at its rear end with a threaded intake adapted for connection to a pipe leading from a source of air and/or steam under pressure. Said intake 32 is in open conununication with the inlet chamber 30.

33 designates an auxiliary air inlet that is adapted to receive free air, as atmospheric air, and deliver it to the chamber 30. Said inlet 33 may be controlled by any suitable type of valve that can be adjusted to deliver any desired volume of free air through the inlet 33 to the receiving chamber 30. As shown, a butterfly valve 3st is employed, the

shaft 35 of which is mounted to rock in the walls of the inlet, and is provided with an operating lever 36. Any suitable means may be employed for locking the valve in adjusted positions. For instance, I may employ a locking plate or'flange 37 fixed to the head and provided witha plurality of openings to receive a locking pin 38 which is adapted to extend through an opening in the handle 36 of said butterfly valve.

The said liquid fuel valve 25 is herein shown as formed on a stem 39 which extends through the fuel inlet chamber 22 in the direction of the inlet connection 21. Said stem is tapered towards its free end and is spirally fluted or otherwise formed to cause the liquid fuel passing thereover under pressure to be given a swirling motion, and to thereby improve the mixing of the liquid fuel and air after the fuel has been discharge d through the port 28 into the fuel constituent mixing chamber. The valve and its stem, as herein shown, have the form of an ordinary wood screw.

Extending across the burner tube 17 near its discharge end is al spreader 40 of any suitable construction to cause the atomized fuel mixture to be spread. at the point of leaving the burner tube so as to strike the tapered side walls of the combustion chamber in the furnace.

ln operation, the valves connected to the air inlet and fuel inlet pipes are opened to admit liquid fuel and air under pressure to the respective chambers 22 and 30. The strength of the sprinfy 26 is such aslto operate against varying liquidi-fuel pressures to deliver the desired quantity of fuel to the head; it being understood that the adjustment is such that the fuel pressure will overcome the strength of the spring to permit delivery of a desired amount of fuel to the chamber 29 through the port 28. Air under pressure passes to the mixing chamber around the member 23 and is mixed with the fuel at a 'time when the fuel is swirling, due to its passage over the spiral convolutions of the valve stem. This mixture is delivered through the mixingv tube l? against the spreader 40 and into the furnace and is there mixed with and directed by the large body of low pressure air that is taken through the casing 10, the air valve 13 of which is adjustably open to admit a desired volume of air.

The auxiliary valve 34C furnishes means whereby air lmay be proportioned to the atomized mixture more closely than such proportion can be afforded by adjustingthe intakes of air and fuel under pressure. The said valve 34 is provided with means for adjusting it through small increments of movement and the air is delivered through the inlet 33 by the force of air under pressure passing through the chamber 30 by way of inlet lt has been found in practice that the use of the auxiliary valve located and operating asshown verysubs'tantially refines the operation of the burner, in that it clarilies the flame and gives perfect combustion and various ranges of temperature.

The location of the inlet 33 as shown in the drawings is of considerable advantage in respect to the unhindered delivery of the free air to the chamber 3l) as well also as producing a symmetrical structure. Y

another feature of advantage lies in the construction and the location of the fuel swirling means at such point that the air is brought at once int-o contact with the swirling fuel so that better conditions are provided for intermixing the fuel and air.

B v reason of the large diameter of the nor,- Zle or discharge orifice end of the conduit ll. relatively to the nozzle area of the elongated combustion chamber 17, the burning mixnnpinO'ed on the material beingheated and avoiding local overheating of said material which would occurif the material were at,-

taclied by the burning mixture under pressure from the tube 17. The valves 13, 34 and the liquid fuel and `pressure air valves can be readily adjusted to produce the most exact effects at the-heating zone inthe furnace; and the free egress fromthe large diameter conduit ll permits unobstructed flow of the air and burning mixture into the furnace, Without restraint except as afforded by the control valves. i

l claim as my invention:

L liquid fuel burner comprisingalow pressure air inlet conduit adapted to4 disi charge air in large volume and atv low pres sure into a furnace, With means to `control the air flow therethrough, and a high pres@ sure mixing chamber in rear of and adapted to discharge its mixture under pressure intoA the furnace through an elongated combustion tube Whose nozzle 1s ydisposed in the core ofthe ,low pressure air discharged .from

said conduit, said high pressure mixing chamber having separate adjustable `nie/airis to supply liquid fuel and air undergviressure to said chamber-and to miX them therein u and to discharge the burning mixture into said tube. i y i 2. A. liquid fuel burner comprising a lon' pressure air inlet conduit :adapted to discharge airin large volume and at low presi sure into a furnace, With means to control the air flow therethrough, a' high pressure mixing chamber in refarwof and adapted to discharge its mixture under pressure into the furnace through an elongated combustien tube Whose nozzle is disposed in the core of the low pressure air discharged fromf said conduit., said mixingy chamber having separate adjustable means 4to supply liquid fuel land air under pressure to said chamber and to mix them therein, and means to suppl air at atmospheric pressureto said high pres-:sure mixing chamber. 1

Il. fi liquid fuel burner comprising a low pressure-air inlet conduit adapted to dis- I rhargeair at lonr pressure and in large volVVA unie into a furnace and provided with a regL 'i valve. a combustiontube having its u'iiice rischargingi' into the airf as fit issues from said conduit. a mixing chamber adapted te discharge' its mixture, through said combustion tube` and separate means 'to sup-- pli' liquid fuel and air under pressure to said chamber and min themtherein for conibustion and for discharge through said tube` und nozzles of said latter tube and of said conduit being coaxial and of such relative discharge y"ai" enable the combined mixture to be gently' eas" as 'tO subduel they burning mixture issuing from `the cemlnistion tube to c'f f.' the high anclfloivc pressure constituent, to impinge softly on the material bcingl'ieated.i y i d. il; liquid fuclfburner comprising a lou' pre ireair inlet conduit having an enlarged free disc large nozzle adapteil to sbs-- charge into a. furnace, and. a high pressurev miiiin. l ou end 'withan elongated combustion tube,` i tube' haring at its other end a discharge noaf/,learra-i red axially in the discharge end oi said'conduit and adapted to discharge. its burning mixture under high pressure into -the furnace throughy the core of the low `pressure air issuing' in large volume from said conduit to the' furnace, separate means to supply liquid fuelandiair under pres sure to said chamber and to mix them therein for discharge into and throughth"e combustion tube, means to supply pheric pressure te said high pressure mit(A ing chamber, and a controlling valve in said loiv'pressure air inlet conduit.

A liduid fuel burner comprising a loir pressure air inlet conduit having an renla dfree discharge nezzleadapted to discharge air in large volume and under low pressure inte a furnace and provided With a controlling salve, a combustion tubeetending' axially through said conduit and having a discharge` orifice restricted relatively to and axially in the outlet ofsaid conduit/,4a high pressure mixing chamijeer connected 'to the rear 'end of said combustion tube, separatemeans te adjust-ably siuiply .liquid fuel and air under pressure to said mii-:ing chamber andto mix them therein1 and anfadjustable free airinlet opi-)ning` al; vthe rear of said mixing chambe 6, A` liquid fuel burner comprising a lou7 pressure, airl inletncondnit of elbow shape, one member'of which terminates in an en* larged unrestricted dischaijge nez/.zie adapted to discharge intoy a furnace, `a controllhig y l te inthe other member lofsaid conduit. a. ombustion tube entre]ulingrlL id first mentioned member, a higigh su ing chamber connectedwte 'the iai' end of Said combustion tube and provided with means-vseparateljfund adjuF-:tibiy to permit the supply of liquid fuel and air under "jf'io said chamber and to ininthem f and means to admit ree air u'xiup; chauiber` the nnazle of said ceiubusn Ltul` i" chai ne' coaxially with the cui i loujpressure air inlet condi,

7. .ln a liquid fuel burnern the combination `with an elongated 'mixing tube and i ts head at the rear end of said tube. of separati meansfor supplying liquid fuel and air t, der their own initial pressures to said head,

"chamber having" communication at air at aimes! ture of the air and fuel underpressure with an inlet open to the atmosphere, separate from the said air supply under pressure,

and an adjusting valve in said inlet.

8. In a liquid fuelburner, a head, separate means for supplying liquid fuel and air under their own initial pressures to the head, constructed with means to mix the fuel elements in the head, and auxiliary means separate from the pressure supply 'means to supply free air to the head for admixture with said fuel elements in the head.

9. In `a liquid fuel burner, a head formed to provide an air inlet chamber, a liquid fuel inlet chamber, and a mixing chamber, a connection to eliver air'under pressi'ire to the air inlet chamber, a connection to deliver liquid fuel under` pressure to ,the fuel inlet chamber, and a valve between said liquid fuel chamber and the mixing chamber, spring held against and adapted to vbe opened by the pressure of the liquid fuel.

10. In a liquid fuel burner, thecombina tion with a. burner tube and a head` formed.

` to provide'anair inlet chamber, aliquid fuel inlet chamber, and a 'mixing chamber, lthe latter in communication with said tube, a connection to deliver air under pressure to the air inlet chamber, a connection to deliver liquid fuel under pressure to the fuel inlet chamber, and a valve between said liquid fuel chamber and the mixing chamber, spring `held against and adapted to be opened by the pressure of the liquid fuel.

11. In a liquid fuel burner, a head formed to provide an air inlet chamber, a Aliquid fuel inlet chamber, and a mixing chamber, a connection to deliver air under pressure `to the fuel inlet chamber, a valve between said liquid fuel inlet chamber and the mixing chamber, spring held against and adapted to be opened by the pressure of the liquid fuel, and means to regulably supply free air to said air inlet chamber.' V

12. In a liquid fuel burner, a head formed t0 provide an air inlet chamber, a liquid fuel inlet chambeigand a mixing chamber, a connection to deliver air under pressure to the air inlet chamber, Ia connection to deliver liquid fuel underpressure to the fuel inlet chamber, a valve between said liquid fuel inlet chamber and the mixing chamber, spring` held against and adapted Vto be opened by the pressure of the liquid fuel, la port opening to said air inlet chamber, 'and open to atmosphere, and a regulating valve in said port.

mix the fuel ele.

13. A liquid fuel burner comprisinga casing having a member adapted to be inserted through the furnace wall, and an angularly disposed member adapted for connection with an air' supply, a valve to control. the flow of air through i tube extending through of the casing, a head connected to said tube, separate means for supplying liquid fuel and yair under pressure to the head, const r'fu'cted with means to mix the'fuel elements in the head and deliver the mixture to said tube, and auxiliary means to regulably supply free air to the'heady for admixture with said fuel elements.

14. `In a liquid fuel burner, a head formed to provide an air inlet chamber, a mixing cliamber,"and a liquid fuel inlet chamber provided therebetween l'and the Imixing chamber with a valve seat, a valve, spring held against the seat, and provided with a spirally fluted stem extending towards the receiving end of said chamber, a connection to deliver air under pressure to the airinle't chamber, and ya connection to deliver liquid fuel under. pressure to the fuel inlet cham'- ber. i

15. ln a liquid fuel burner, a head formed to provide 'an air inlet chamber, a mixing chamber, and a liquid fuelI inlet chamber provided therebetween and the `mixing chamber with a' valve'seaaa valve, spring held against the seat, and provided with a spirally iiuted stein extending towards the receiving end "of said ehamber, means to vary the force of the spring acting'against said valve, aycon'nection to deliveiair under pressure t0' the air inlet 'chamber'.y and a connection to deliver liqiiid"fuelunder pressure to thefuel inlet chamber.

' a liquid yfuel burner, a head formed to provide an 'air inlet chamber, a mixing chan'iher. and a' liquid fuel inlet chamber provided therebetween and 'the mixing chamber withfa valve seat,'a'valve, spring held against ythe seat, and provided with aspirally 4fluted'stem extending towards the receiving end of said'chamber, a connection to deliver air under pressure to the airv inlet chamber, a connection to deliver liquid fuel under A'pressure 'to' thel fuel inlet chamber, and auxiliary means to' 'regulably supply free air l t fthe head for admixture with the fuel elements delivered under pressure to the head.

'In witness whereof l claim the foregoing as'my invention, l hereunto append my signature at Blorn'niirgtonl,v Illinois, this 18 day of April, 1919. "f

` rJOHN THOS. MCGRATH.

said casing, a burner. `the outlet chamber 

